Question
Two resistors of resistances R and 2R are connected in parallel with a battery of electromotive force (e.m.f.) 12V and negligible internal resistance.
The total power dissipated by the two resistors is 36 W.
What is the value of R?
(A) 0.5$\Omega $
(B) 2.7$\Omega $
(C) 4.0$\Omega $
(D) 6.0$\Omega $
▶️Answer/Explanation
Ans: D
Question
A resistor of resistance R is connected across a cell of electromotive force (e.m.f.) E and negligible internal resistance.
Which single change to the circuit would lead to the largest increase in the power dissipated in the resistor?
(A) doubling the value of E
(B) doubling the value of R
(C) halving the value of E
(D) halving the value of R
▶️Answer/Explanation
Ans: A
Question
What is the definition of the potential difference across an electrical component?
(A) the charge per unit time passing through the component
(B) the energy transferred per unit charge
(C) the force per unit charge
(D) the resistance per unit current
▶️Answer/Explanation
Ans: B
Question
What are the definitions of potential difference (p.d.) and electromotive force (e.m.f.), in terms of energy transfer W and charge q?
▶️Answer/Explanation
Ans A